Danner® Manufacturing 21025 Replacement Rotor for Pondmaster® 6600 Hy-Drive Pump. The Pondmaster® Hy-Drive water pumps are rugged, powerful and efficient. The compact size makes it ideal to use in larger ponds, skimmers, waterfalls or anywhere that space is tight. All pumps come with a full set of fittings and include a free pump bag for extra pump protection.